Brush structure and holder



y R. e. ANDERsbN ET AL 2,324,461

BRUSH STRUCTURE AND. HOLDER Filed March 15, 1941 INVEN O 5 lgflnderson y I Wdooson ATT QRN Patented July 13, 1943 BRUSH STRUCTURE AND HOLDER Raymond G. Anderson, We stOrange, and Wil liam T. Jacobson, Clifton, N. J., assignors to The Roto Company, a corporation of New Jersey Application March 15, 1941, Serial No. 383,536

7 Claims.

Our invention relates generally to new and useful' improvements in brush structures and holders therefor, as well as a new and improved method of manufacturing brushes of the type which are commonly employed in the cleaning of relatively small diameter boiler tubes, condenser tubes and the like.

It will be understood, of course, that brushes of this character have a wide application in industry apart from the beforementioned uses and that it is contemplated that the invention may be employed in any and all such environments. As presently manufactured, these brushes consist of a plurality of individual brush elements symmetrically positioned in a common holder which may be rotated by power or manual means.

In connection with a consideration of the physical characteristics imposed upon such brushes by the uses to which they are put, it is important to note that the tubes which they are employed to clean are commonly as small as 1" in diameter, so that the structure must be exceedingly compact; Furthermore, it has been found that the diametrical limitations thus imposed upon the size of the brush, preclude the possibility of successful recourse to mechanismwithin the brush or holder to yieldably urge its elements to brushing contact with the walls of tubes of varying diameter.

It will be obvious, however, that any slight variation in the internal diameter of the tubes would render a brush comprised of fixed elements ineifective. Hence such a structure, to be adaptable to other than very limited service must needs incorporate either provision for manual adjustment of the diameter of the brushes, or in the alternative, its elements must float, or be otherwise so automatically 'flexible'as to accommodate themselves to tubes of varying diameter. r

Yet another practical consideration involved in the construction of the brush element, is that which results from the normal tendency ofthe brush to foul when utilized in the cleaning of tubes which may be coated with gums or sticky substances such as milk residue, carbohydrates, or hydrocarbons. Hence, the brush structure, as well as its holder, must be capable of disassembly and re-assembly for the purpose of cleaning and inspection of its parts. 'The' desirability of access for repair and replacement also arises in the cleaning of scale from boiler tubes where surface conditions are sufiiciently severe to result in wearing of the brushes,-with an-accompanying' necessity for frequent renewal of parts.

Thus, it is one object of the invention, to provide a'brush of the character described in which the brush elements are capable of automatically adjusting themselves to varying diameters of tubes as well as to such variations as may occurin the diameter of any given tube, for example, from the adherence of foreign matter to the interior surface of the tube.

Another object of the invention consists in the provision of a brush of the character described which :adapts itself to ready assembly. and disassemblyforthe purpose of replacing its parts.

, 'Yeta-different object resides in the provisionof 'a brush of the character referred to, in which theindividual brush elements thereof automatically act to compensate for wear so as to insure engagement with the surface to be brushed;

A further object of the invention resides in the provision of a brush structure which will be ecolindrical body portion formed with radially extending slots having opposed parallel side walls adapted to journal the brush elements, and a single removable cap effective to render said brush elements accessible for removal and replacement.

Another object provision of a new and improved method of man.-

ufacturing brush elements of, the character described, in whicha succession of, related but simple. manufacturing operations, contribute to the economical production of a new and improved 'brush structure. I l

. Other objects and advantages will be apparent 'in the following description, taken in connection with the accompanying drawing in which;

Fig. 1 is a perspective view of a bar utilized in the construction of a brush element.

Rig. 2 is a perspective view of the bar shown in F process; v

Fig.3 represents the bar of Figs. 1,. and 2 in a third step of the manufacturing operation.

Fig. 4 is a crosssectional view of the bar of manufacturing process.

assembly and disassembly of the of the invention consists in: the

in a later stage of the manufacturing l gs. 1-3 inclusive, following the last step in the Referring now particularly to Fig. 1, in which we have illustrated an initial step in the improved method of manufacturing a brush element.

In this view, as well as in Figures 2 to 5 inclusive, the body of the brush element is illustrated in an inverted position to more clearly demonstrate the manufacturing process.

An elongated bar of substantially square cross section, is cut in equal lengths to form brush element bars II], the inner faces of which are identified by the numeral II, the outer or'external faces being shown at I2.

The external surfaces of bar elements ID, are

undercut on a radius r to form similar steps 13, of equal depth extending longitudinally from the respective ends of the bar.

The bar is next drilled to form a series of equally spaced apertures I4, the axesof which preferably coincide with the longitudinal axis of the bar. 1

These apertures extend completely through the bar and are utilized as will hereinafter appear, to receive independent tufts of bristles. Of course it will be understood that the apertures I4 may .be drilled singly, or in the alternative, where gang l '-of the slot I5 as shown by the numerals and its ends terminating substantially flush with the ends of the bar. The tufts are now drawn down upon the pin 23, whereupon a second overlying rigid pin or bar 24, is positioned in the slot I5 so as to retain the tufts in assembled position in the bar. The rod may be rigidly retained in tuft holding position in the slot I5, as for example, by soldering or welding." We prefer, however, to peen 'the end apices defined between the inclined surfaces IT and I8, and the'side Walls added safeguard against the possibility of the rod 24 being dislodged intermediate its ends, we

drilling equipment is used, they may be formed inmultiples prior to cutting of the stock material into the finished lengths illustrated by the piece I0. 7

Subsequent to .the beforementioned drilling operation, the bars III are milled on a line corresponding with their longitudinal axes to form a narrow kerf, or slot I5, which extends from the under surface II to a line I6, substantially coincident with the median line through the center of the bar. Here again, it will be apparent that this. operation" may be automatically accomplished priorto cutting of the bar stock into the lengths shown in the drawings or, the individual pieces may be successively fed into operative engagement with a milling cutter.

, Referring now to Fig. 3, which illustrates the bar following the last step in its manufacturing operation, it will be noted that the opposite par- :allel side walls I! and I8 are cut from their inner edges, as for example, by milling or grinding, to form angularly disposed converging faces I9 and 20. The faces I9 and 20 will be seen to intersect the lines formed by the kerf I5 in the under surface of the bars so as to provide the appearance of a succession of spaced parallel webs 2| through each one of which the kerf I5 extends downwardly to the line I 6. Like the previously described manufacturing "operations, the formation of the inclined faces I9 and 20 lends itself to a simple automatic machine operation which may be accurately and inexpensively formed as'the last one of a succession of related steps.

As fully shown in Figs. 4 and 5jindividual tufts of=loopedbristles22 are inserted in the apertures I4 from the external surface, I2 of the bar. The tufts are forced through the respective apertures until the inner portions of their loops clear the line I6 of the bottom of slot I5, Whereupon a rigid pin 23 is passejd through the loops,

may peen the intermediate pairs of apices 21 and 28'which are formed between successive aper tures I4, as a result of the combined drilling and edge milling operations. Thus, the rod 24 is capable of being held at five separate points throughout itslengthimeach bar containing four tufts of bristles.

Now coming to theconstru o tion olf'the brushv holder illustrated in Figs. -6 and '7:

The holder includes amain bodymember 30 of circular cross section which-may'accordingly be manufactured from a stock rod material. This body member ismilledgtoform a plurality of longitudinally extending radial slots 3| the number being dependent upon the number of brush. elements tobe employed.

A shown'particularly in 7, they slots 3I comprise inwardlyextending parallel side walls 32; and 33, spaced apart ;.toffreely. journal the side faces-I1 and I8 ofthe brush elements III.-

Adjacent their inner ends,'the side walls 32 and 33 of slots 3I converge on an angle of substantially 45 degrees as shown-at 34 and 35,'to define angles similar to the angularity of the faces I9 and 20 of the brush elements III.

It will now be observed-that the economy of space which is effected intheformation of the faces I9 and 26 of the brush elements, as-distinguished from bending a solid wall of the bar into engagement with the bristles, results in relatively greater movement of; the brush elements from their extreme inner to their outer positions, as defined by the solid and broken outlines in Fig. '7. In other words, the construction of the brush elements forms a relatively shallower unit than has heretoforebeen provided, and this feature in turn makes ,for a greater range of usefulness-of the unit because it is capable of adapting itself to a wider: rangeof. tube diameters. In the construction illustrated, for example, the brush unit is capable of operation in tubes; ranging from ofv an inch in diameter to 1 in diameter with maximum efiiciency undercut-at itsforward or-leading endas shown at 36 to receive a circular end'cap 31 the internal 'cylindrical surface of which'is formed on the radius -r. Cap 31- may. be; permanently secured to the body by swedging or any other desired ,The rear, is similarly undercut as shown at 38, to receive a removable cap 39, which, like cap3'l, is formed ,with an internal surface havin the radius ,r.

..Cap ;39gis additionally provided with an axial --ape rture permitting free-sliding movement one.

threaded stud 40 formed gintegrally with the y mber-. 5 a y a or following end of the body member,

stud 40, is effective to hold the cap 39 in position. Referring again to Figs. and- 6, it, will now be apparent that the undercut ends I3 of the brush.

elements, engage the forward fixed cap 3'! and the removable cap 39'respectively, when centrifugal force acts to throw the brush elements to the outer limits of their movement.

Furthermore, it will be seen that removal of the nut 4!, followed by sliding of the cap 39 from the stud 40 will permit removal of the brush elements for cleaning or replacement.

2,324,461 A nut 4!, arranged to threadably engage the position in said kerf to prevent dislodgment of said bristles.

3. A brush element for boilertube cleaners,

comprising in combination, a bar having outer, spaced parallel side walls, and inner converging side walls which merge with said parallelwalls' I on a line substantially coincident with the plane It will additionally be observed that the unitary free sliding movement in their respective slots;

Hence, the'brush elements will always freely operate under the influenceof centrifugal force to move outwardly to the position in which their bristles engage the surface of the tube to be cleaned. K n

We claim as our invention: l l

1. The method of forming a brush element which comprises the steps of drilling an elongated bar to provide a plurality of equally spaced apertures extending in a line coincident with the center line of said apertures to a depth corresponding substantially with the median line thereof to form a narrow kerf, then cutting away the inner parallel edges of the bar on an angle of substantially 45 degrees to provide in conjunction with the walls of said kerf, and said apertures, a plurality of separate pairs of apices spaced along the-bar in pairs, then feeding tufts of looped bristles into each of said apertures from the external surface of the bar to a point where the interior loop of the tufts is spaced below the beforementioned median line of the bar, then passing a pin along the bottom of said kerf and through said loops, drawingsaid tufts of bristles outwardly into engagement with said last mentioned pin, laying a second] pin in said kerf in overlying engagement with the outer loops;

of said bristles, and finally, peening the beforementioned apices formed between the walls of said kerf and the cutaway edges of the bar to wedge of said last mentioned pin in said kerf.

2. The method of forming a brush element which comprises the steps of drilling an elongated bar to provide a plurality of apertures extending therethrough, then milling the internal face of the bar throughout itslength on a line intersecting said apertures to form a narrow kerf, then cutting away the inner parallel edges of the of the median line of the bar, said bar being formed with a plurality of apertures, the respective axes of which define a plane parallel to the planes of 'said beforementioned side walls, said bar also being formed with a kerf extending long'itudinal thereof from the apex defined by said converging side walls to a line substantially coincident with the median line through said bar, a tuft of looped bristles arranged in each said aperture, a pin in the bottom of said kerf and extending through said loops to prevent said tufts of bristles from being dislodged in one direction,

a second pin in said kerf, in overlying relation with respect to said loops of said tufts of bristles to prevent dislodgment of said bristles in a second direction and means to prevent said last mentioned pin from being dislodged from said kerf.

4. A brush element for tube cleaners, comprising in combination, an elongated bar having. spaced parallel side walls to define bearing surfaces, said bar being formed with a plurality of apertures, the respective axes of which lie parallel to the planes of said side walls, and a longitudinal kerf intersecting'said apertures, tufts of bristles arranged in each said aperture, and a bar rigidly supported in said kerf in overlying relation with respect to said bristles to prevent dislodgment thereof.

5. A-brush holder of the character described, comprising in combination, a cylindrical body member, saidbody member beingformed with a plurality of radially extending slots, said slots being characterized by an outer portion consisting of parallelside walls and an inner portion in which said side walls converge toward the axis 7 of said body member, a cap rigidly secured to 7 comprising in combination, a bar, said bar being bar on an angle of substantially 45 degrees, to

provide in conjunction with the walls of said 'kerf, a pair of apices at each end of the bar, then feeding tufts of bristles into each of said apertures from the externalsurface of the bar to a point where the interior loop of the tufts is spaced below the bottom line of said kerf, then passing a pin along the bottom of said 'kerf and through said loops, drawing' said tufts of, bristles outwardly into engagement with said last mentioned pin, laying asecond pin in said kerf in overlying,

engagement with the outer loops of said bristles and finally, securing said last mentioned pin in one end of said body member, and a second cap removably secured to the opposite end of said body member.

6. A brush'holder of the character described, comprisingin combination, a solid cylindrical body member, said body member being formed with a plurality of longitudinally extending radial slots; said slots being characterized by an outer portion consisting of parallel side walls and an inner portion in which said side walls converge toward the axis of said body membena cap rigidly secured to one end of said body member and a second cap'removably secured to the opposite end of said body member.

'7. A brush element for boiler tube cleaners formed with a plurality of apertures, the respective axes of which define a plane extending parallel to the longitudinal axis of the bar, said bar having a longitudinal kerf intersecting said apertures, a tuft of looped bristles arranged in each said aperture, a pin lying in the bottom of said kerf and extending through said loops to prevent said tufts of bristles from being dislodged in one direction, a bar in said kerf, in overlying relation with respect to said tufts of bristles to prevent dislodgment of said bristles in a second'direction, and means to prevent said bar from being dislodged from said kerf.

' RAYMOND G. ANDERSON.

WILLIAMT. JACOBSON. 

